1) Get an Agent. To make sure you've found the right one follow them around, go through their bins and consider breaking into their house and going through their underwear.
2) Buy a really flashy laptop or Ibook so you look cool in the coffeeshop.
3) There are thousands of books out there that hardly anyone read, why not do their authors and yourself a favour by 're-tasking' them?
4) Criticism is another word for jealousy.
5) If anyone turns you down, send them an abusive email or ring them up and scream at them. That way they know you are serious.
6) Real writers don't have time for personal hygiene.
7) Tell everyone you've been published in a lot of very prestigious places, no one checks this sort of stuff.
9) Never mention the number eight, it's unlucky.
10) Christopher Booker wrote a really boring book called The Seven Basic Plots. You don't need to bother reading it but point people at that next time someone says, 'Plagiarism'.
11) There are a lot of other writers out there and each one will be trying to get the book deal you deserve. Kill as many as possible.
12) 'You may want to edit this' is another way of saying 'I hate you for your talent and wish to wreck your work.'
13) If at first you don't succeed, Publishamerica.
14) Tell people you're a poet, no one understands poetry anyway and you will appear mysterious.
15) Get an eye-tooth from a twice-bestselling novelist and place it under your pillow. In the morning the publishing fairy will have replaced it with a three book contract. (Thank you to @E_M_Edwards on the Twittermachine for this invaluable tip.)
16) Make spurious lists to mislead the competition.
17) Join the Association Of Really Real Actual Writers!
For those interested here are some handy tips on how to submit a manuscript.
(Please, add your own tips in the comments.)